Containers for transporting and disposing of recalled airbag inflators

ABSTRACT

Embodiments described herein include layered mesh containers and methods for using the containers to safely transport and dispose of airbag inflators having ammonium-nitrate-based propellant. For example, a container is provided that can hold multiple airbag inflators and withstand up to  4  moles of matter being deployed from an inflator having ammonium-nitrate-based propellant. The container can contain the inflator and any shrapnel associated with the explosion while also venting gases expelled as a result of the explosion. Various container designs are provided, along with methods for using these containers.

CROSS REFERENCE TO RELATED APPLICATIONS

This nonprovisional patent application is a continuation of U.S. patentapplication Ser. No. 15/360,910, entitled (“Transporting and DisposingRecalled Airbag Inflators”) and filed on Nov. 23, 2016. This applicationclaims priority to U.S. patent application Ser. No. 15,360,910, whichclaims priority to U.S. provisional patent application No. 62/336,558(“Process and Apparatus for Transportation and Disposal of RecalledAirbag Inflators”), filed May 13, 2016, and further claims priority toU.S. provisional application No. 62/401,142, filed Sep. 28, 2016, all ofwhich are incorporated by reference in their entireties.

FIELD OF THE EMBODIMENTS

The embodiments described herein related to transporting and disposingof recalled airbag inflators using ammonium nitrate propellant, andspecifically barrels constructed and used for doing so.

BACKGROUND

Airbags for passenger vehicles commonly use an “inflator” to inflate theairbag in case of an emergency. A typical inflator includes an ignitorand a propellant that inflates an airbag in the event of a vehiclecrash. One of the world's largest airbag suppliers—Takata®—has produceda large number of defective airbag inflators. As of November 2016, over100 million Takata® inflators have been recalled worldwide. The scale ofthis recall has introduced safety, logistical, and environmentalchallenges involved with transporting and disposing of explosive andunstable airbag inflators.

The defective inflators use ammonium nitrate (“AN”) propellant. Whiledesigned to deploy upon receiving an electrical current at theinflator's initiator pins, the defective inflators can also deploy withexposure to an external heat source such as fire. According to newssources, the current, unregulated process of transporting recalledTakata® airbags has already caused at least 16 deaths. As a result, acomprehensive protocol for ensuring safe transport and disposal ofrecalled inflators is needed.

To gain approval for shipping on U.S. roads, all production automotiveairbag inflators and energetic assemblies, such as seat beltpre-tensioners, are subjected to a Department of Transportation (“DOT”)“bonfire” test. Europe's DOT equivalent, BAM, requires a similar “gasburner” test. Both the DOT and BAM tests involve exposing airbaginflators to an open-flame heat source sufficient to cause auto ignitionof the inflator's main generant bed. To pass the test and be approvedfor shipping, an inflator must function without fragmenting due to theexternal heat source. Bonfire testing is the most rigorous structuraltest of an AN-based inflator design because ammonium nitrate propellantcan melt before it burns, resulting in conditions inside the inflatorthat amplify challenges of ensuring the design does not failstructurally during the open flame deployment scenario.

The U.S. government, and other governments around the world, will likelyclassify AN-based airbag inflators as explosives or change the existingclassification for recalled inflators. That new classification (orreclassification) would prevent traditional shipping methods from beingused to transport these inflators. AN-based airbag inflators that areknown to fragment due to over pressurization of the inflator's pressurevessel housing during normal deployment conditions at ambient outsidetemperature are generally expected to fail at a higher rate (or are morelikely to fail) when exposed to an external heat source such as DOTBonfire testing. An inflator sample population that exhibits anystructural failures when deployed at ambient temperature is likely toexhibit a significantly higher rate of structural failure when anexternal heat source causes the inflator to deploy. This is becauseoperating pressure of the inflator's internal combustion chamber tendsto increase with temperature, while the steel pressure vessel strengthdecreases with temperature. This problem can become significantly worseif propellant melts.

Common auto-ignition materials ignite at temperatures above 130° C.,which is significantly higher than any upper temperature limit theinflator design was intended to operate at during normal deploymentconditions. Hence, an inflator suspected of structural failure whenfunctioning at ambient temperature has an increasing likelihood ofstructural failure as temperature increases. Defective AN-based Takata®inflators can fragment even at ambient outside temperatures. Thus, theyare expected to fragment more frequently if exposed to an external firesuch as the DOT Bonfire test. These defective inflators are thereforenot fit to be shipped using traditional methods used for non-defectiveinflators.

Currently, these recalled inflators are being shipped in steel drumswith lids secured with tape, or in cardboard boxes, depending on therelevant state laws. These state laws have proven ineffective, asillustrated by a fatal explosion of a truck transporting recalledTakata® inflators in August 2016, in Texas. In some cases, speciallydesigned thick-walled metal containers are being used to transportrecalled inflators. However, these containers are expensive to build andare not suitable for mass production on the scale required for thecurrent recalls. Lack of a common protocol at the national and globallevels for the handling, packaging, storage, and shipment of inflatorscontaining unstable ammonium-nitrate-based propellant may result infurther human injury as well as economic and environmental damage.

As a result, a need exists for a nationally implementable, low-costmethod for transporting recalled inflators. Safety concerns can beaddressed with a process of modifying common containers or entirevehicles to achieve a structure and method suitable for the safe, bulktransport of recalled inflators using materials that are common acrossthe continent, nation, or state. A method of construction and validationof the proposed shipping container designs is described for both largeand small scales below.

SUMMARY

Layered mesh containers and methods of using the containers aredescribed herein for safely transporting and disposing of recalledammonium-nitrate-based airbag inflators. In one example, a method isprovided for loading the inflators into a container having mesh layersand transporting the container to a disposal site. The method caninclude, for example, placing multiple airbag inflators in thecontainer. The container can withstand a deployment of an airbaginflator that releases up to 4 moles of gas. The layers of mesh cancontain the detonated airbag inflator and shrapnel associated therewithand allow gas associated with the detonation to exit the barrel. In oneexample, the method can include shipping the container to a deploymentsite, where the inflators are heated up to allow a controlleddeployment.

The words “detonate,” “explode,” and “deploy” are used interchangeablyherein, and can refer to any condition where the metal housing fragmentsor fails, and/or propellant exits the body of the inflator, eitherintentionally or unintentionally. The propellant, along with any otherchemicals or substances within the housing of an airbag inflate, can becollectively referred to as “energetics” or “energetic material.”

The method can further include positioning the container in or on atransport vehicle. For example, the method can include using a forkliftto lift the container from a first location and place the container inthe bed of a truck. In some examples, the container can be placed in aconstruction-grade vehicle such as a dump truck. This portion of themethod can also apply to vehicles other than road-going vehicles, suchas ships or planes. In one example, the method includes placing thecontainer in an intermodal shipping container which is then place on atruck or ship.

The method can also include measuring a first weight of the containerincluding the live airbag inflator. The method can further includeapplying heat to the container sufficient to deploy the live airbaginflator. In some examples, this includes heating the container suchthat the inflators reach a core temperature of at least 130 degreesCelsius. In some examples, the container is heated such that theinflators reach a core temperatures of at least 180 degrees Celsius.This can include, for example, heating the container via convection,conduction, or radiation. In order to ensure complete disposal of aninflator, the inflator must reach auto-ignition temperature. The maingenerate bed of an inflator will typically automatically ignite attemperatures between 130 and 185 degrees Celsius. Therefore, in someexamples, the inflators are heated to a temperature of about 200 degreesCelsius to ensure ignition.

A second weight of the container can be measured after applying theheat. Based on initial information such as the weight of the containerand the number of inflators in the container, the difference between theweights can inform whether the inflators deploy, and if so, how manydeployed. Based on the difference being above a threshold value, thedeployed inflator(s) can be removed from the container.

In one example, a temperature sensor can be used to measure thetemperature of an inflator in the container. In another example, thecontainer is placed inside a disposal container prior to heating thecontainer. The disposal container can be heated in addition to heatingthe container.

The container can take a variety of different forms. In one example, thecontainer includes multiple lattices coupled to one another to form anenclosure. The enclosure can be shaped to contain multiple airbaginflators. At least one of the lattices can be coupled to anotherlattice via a rotatable coupling that allows a user to open and closethe container. Each lattice can be strong enough to withstand deploymentof one or more airbag inflators without substantial deformation of thelattice. Substantial deformation can include, for example, deformationsufficient to compromise the structural integrity of the lattice orotherwise allow any solid portion of the airbag inflators to exit theenclosure upon deployment. The lattices can be made from metal strandshaving sufficient thickness to provide the desired strength. Forexample, each strand can have a thickness of between about 0.04 inchesand 1 inch.

Continuing the example, the container can include a mesh layerpositioned on an inner surface of at least one of the lattices. In someexamples, the mesh layer can be positioned on inner surfaces of all thelattices making up the enclosure. The term “surface” is used broadly, asthe lattices can be constructed from metal strands and therefore nothave a continuous inner or outer surface. However, the inner and outersides of the plane formed by the lattice can be considered surfaces forthe purposes of this disclosure.

The mesh layer can include apertures or perforations sized to allowpassage of gas while preventing passage of shrapnel from a deployedairbag inflator. For example, the apertures can be sized to prevent asphere having a diameter of at least 0.9 inches from passing through themesh layer. The container can also include an environmental barrierlayer positioned on an outer surface of at least one of the lattices.The environmental barrier layer can include a material, such as plasticor a high-temperature, fire-retardant silicone foam, that preventsmoisture from passing through that lattice. In some examples, theenvironmental barrier can be attached in such a way that it rips ordetaches from the container to allow sufficient venting in the event ofan inflator deploying.

In another example, a container can include a cylindrical sidewall and asolid cap coupled to a first end of the cylindrical sidewall. Forexample, the container can include a metal barrel with one end weldedclosed. The container can also include a vented cap removably coupled toa second end of the cylindrical sidewall. The vented cap can be shapedto allow passage of gas through the vented cap while preventing passageof shrapnel from a deployed airbag inflator. For example, the vented capcan include apertures sized to allow passage of gas but not shrapnel.

Continuing the example, the container can include a baffle positioned toredirect shrapnel from a deployed inflator away from the vented cap. Thebaffle can include, for example, one or more metal plates positionednear the vented cap. The baffle can be coupled to the cylindricalsidewall or to the vented cap. An environmental barrier can be coupledto the vented cap to prevent moisture from penetrating the container.

In yet another example, a container can include multiple solid metalsidewalls coupled to one another. In that example, at least one side ofthe container can include a lattice or grate that allows passage of gasbut retains the inflators and any shrapnel associated with a deployedinflator. At least one of the solid metal sidewalls can be rotatablycoupled to another sidewall such that a user can open and close thecontainer.

A detailed description of these examples, and other examples, isprovided below. Both the foregoing general description and the followingdetailed description are exemplary and explanatory only and are notintended to restrict the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate various embodiments and aspects ofthe present invention. In the drawings:

FIG. 1 is an illustration of an example container for safelytransporting and/or disposing of airbag inflators.

FIG. 2 is an illustration of an example container lid that includes abaffle built into the lid.

FIG. 2A is a cross-sectional view of the example container lid of FIG.2.

FIG. 3 is a diagram of an example container including a baffle andshowing example travel paths of shrapnel and gas from a deployedinflator.

FIG. 4 is an illustration of an example container including an outerstructural lattice and example inner mesh layers.

FIG. 4A is an expanded view of an example inner mesh layer of FIG. 4.

FIG. 4B is an expanded view of an example inner mesh layer of FIG. 4.

FIG. 4C is an expanded view of an example inner mesh layer of FIG. 4.

FIG. 5 is an illustration of an example container with multiple solidsides and a grate that allows gas to escape the container.

FIG. 6 is an illustration of an example container inside a disposalcontainer, showing the path for gases to escape both containers.

FIG. 7 is a diagram of an example system for disposing of airbaginflators and extracting power from the gases expelled from theinflators.

FIG. 8 is a flowchart of an example method for handling airbaginflators.

DETAILED DESCRIPTION

Reference will now be made in detail to the present exemplaryembodiments, including examples illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

This disclosure describes a variety of containers that can be used tosafely transport or dispose of airbag inflators. While these containers,and the methods of using them, can be applied to any type of airbaginflators, they are also intended to safely handle recalled airbaginflators produced by Takata®. Due to manufacturing defects, theserecalled inflators have an increased likelihood of exploding whensubjected to heat. References to “inflators” or “airbag inflators”herein are also assumed to encompass the recalled defective inflatorsfrom Takata®.

The containers described herein can be used for transporting inflators,disposing of inflators, or both. During the transportation stage, acontainer should provide safety from explosions while also aiding a userin filling the container, locking the container, and loading orunloading the container on or off a vehicle. Of course, the containermust also be able to withstand forces generated from structural failureof inflator housings inside the container while venting gasesappropriately.

At the disposal stage, a container can be used to intentionally deployinflators by applying heat, such as fire, to the container. In thedisposal process, the container might experience high temperaturesand/or come in direct contact with an open flame. The container shouldbe able to withstand these temperatures while still retaining allshrapnel related to inflator deployment and venting gases appropriately.Ideally, the container should be reusable. In some examples, thecontainer can be used both for transportation and disposal, improvingefficiency of the overall recall process.

Containers can come in a wide range of sizes. On the small end of thespectrum, a container can be sized to hold a single inflator. On theother hand, a container can be sized to occupy the bed of a dump truckor a large, intermodal shipping container. In some examples, a containercan be sized between these two extremes, such that the containers can beeasily moved while also holding a moderate number of inflators. Forexample, a container can be sized to accommodate a forklift, allowing aforklift operator to handle the containers without getting closer thannecessary.

Due to the extent of the Takata® recall, many containers may need to beconstructed. To keep costs low, these containers can be constructed fromreadily available materials. For example, FIG. 1 shows a container 100that is based on a commonly available steel drum. That drum, denotedcylinder 110 in FIG. 1, can include a cylindrical sidewall as well as asolid cap coupled to the bottom end of the cylinder 110. As shown in thedrawing, the cylindrical sidewall need not be a perfectly shapedcylinder. Instead, it can include structural ridges, a lip at the topand bottom, and other variations. Although cylinders provide morestrength per volume, other shapes can be used as well, such as arectangle. The cylinder 110 can be made from a heavy gauge steel, suchas 16-Ga or thicker.

The container 100 of FIG. 1 also includes a shrapnel barrier 120. Theshrapnel barrier 120 can be constructed such that shrapnel from adeployed inflator cannot pass through the barrier, while gases emittedfrom the deployed inflator can pass through. For example, the shrapnelbarrier 120 can include a mesh, screen, grate, fencing, or lattice sizedto accomplish these goals. In another example, the shrapnel barrier 120can be a solid plate with apertures that accomplish the same goals. Ineither case, the shrapnel barrier 120 can include openings—such as anaperture or a space between four strands of a mesh—that are one squarein or smaller. In some examples, shrapnel barrier 120 includes openingsthat are 0.5 square inches or smaller. In other examples, shrapnelbarrier 120 includes openings that are 0.25 square inches or smaller.

Shrapnel barrier 120 can be made from a resilient material, such assteel, to ensure that deployed inflators and the resulting shrapnel doesnot damage the shrapnel barrier 120 and form larger openings that canallow shrapnel to pass through. The shrapnel barrier 120 can be aremovable component, as shown in FIG. 1, or can be part of the cylinder110 or the lid 130. For example, the shrapnel barrier 120 can be weldedto the top of the cylinder 110. In that case, the cylinder 110 caninclude a door on the side for loading and unloading the container.

FIG. 1 also shows a lid 130 that can be removably or rotatably coupledto the cylinder 110 and/or shrapnel barrier 120. For example, the lid130 can be secured to the cylinder 110 via a hinge joint 132 and alatching mechanism. The hinge joint 132 can be coupled to the cylinder110, such as by welding, to ensure that the lid 130 stays attached tothe cylinder 110. The latching mechanism can include a componentattached to the cylinder 110 and an associated component attached to thelid 130. These two components can interact to form a latching mechanism.Alternatively, those components can be integrally formed into thecylinder 110 and lid 130, respectively.

The lid 130 can include openings 134 to allow gases to vent from thecylinder 110. For example, the lid 130 can be made from one or moresolid pieces of steel with multiple apertures formed in the lid 130. Inone example, the lid 130 includes apertures formed by drilling. Inanother example, the lid 130 includes apertures punched through the lid130. In yet another example, the lid 130 includes a mesh portion thatallows gas to vent. The mesh portion can include, for example, a sectionof a chain-link fence.

When used with a shrapnel barrier 120, the openings 134 in the lid 130can be larger than the openings in the shrapnel barrier 120. Forexample, the openings 134 in the lid 130 can be between about 0.5 toabout 8 square inches. The total surface area of the openings 134 in thelid 130 should be sufficient to allow gas to flow through at a rate thatprevents unwanted pressure build-up in the container 100. In someexamples, the total surface area of the openings 134 in the lid 130 isequal to, or greater than, the total surface area of the openings 134 inthe shrapnel barrier 120.

The container 110 can also include an environmental barrier 140. Theenvironmental barrier 140 can be made from a moisture-impermeablematerial, such as a plastic sheet. The environmental barrier 140 can besized to cover the lid 130 and/or shrapnel barrier 120, preventingmoisture from entering the openings in the lid 130 and/or shrapnelbarrier 120. The environmental barrier 140 can be secured to thecontainer 100 using, for example, a band 150 as shown in FIG. 1. Theband 150 can be sized such that it stretches to fit around the cylinder110, with the environmental barrier 140 under the band 150. The tensionin the band 150 can keep the environmental barrier 140 in place. Othermechanisms can hold the environmental barrier 140 in place, such asattaching the barrier 140 to a hook attached to the cylinder 110.

The environmental barrier 140 can be designed and attached such that itprevents moisture from entering the container 100 when attached, butalso allows gas to vent from the container 100 in the event of adeployment. In one example, the band 150 maintains tension sufficient tohold the environmental barrier 140 in place under normal circumstances,but allows the environmental barrier 140 to release when subjected to ahigh-pressure event such as an airbag inflator deployment. For example,when an airbag deflator explodes, the resulting pressure can force atleast a portion of the environmental barrier 140 to release from underthe band 150, allowing the gas to escape. In another example, thepressure due to a deployment can cause the environmental barrier 140 torip. This can provide a visual cue to determine whether any inflators ina container 100 have deployed.

FIG. 2 provides an illustration of an example lid 200 that includes abaffle built into the lid 200. The lid 200 of FIG. 2 can be used withthe container 100 of FIG. 1, or any other cylindrical-shaped container.The lid 200 can be secured to a container using the mounts 240. In oneexample, the mounts 240 can include removable pins that can interfacewith both the container and the lid 200. In another example, one mount240 is a hinge mount coupled to both the container and the lid 200,allowing the lid 200 to rotate about the hinge for opening and closingthe container. In that example, the other mount 240 can include alocking mechanism.

The lid 200 can also include an upper baffle plate 220 and a lowerbaffle plate 230. The baffle plates 220, 230 can be oriented such thatshrapnel from a deployment within the container is unlikely to escape.As shown in FIG. 2A, the lower baffle plate 230 can be oriented suchthat it is perpendicular to a longitudinal axis of the container (notshown). Shrapnel traveling in a direction parallel to the longitudinalaxis of the container would likely contact the lower baffle plate 230and be redirected back down. Some shrapnel traveling parallel to thelongitudinal axis can miss the lower baffle plate 230 and insteadcontact the upper baffle plate 220. However, the upper baffle plate 220is also oriented perpendicular to the longitudinal axis, which wouldtherefore redirect shrapnel back down into the container.

If shrapnel enters the space between the upper and lower baffle plates220, 230 traveling in a trajectory that is not parallel with thelongitudinal axis of the container, a grate 250 oriented between thebaffle plates 220, 230 can block the shrapnel from passing through thelid 200. The grate 250 can be any type of material that blocks shrapnelbut allows gas to pass through. For example, the grate 250 can be a wiremesh, a metal plate with openings in it, parallel slats, chain-linkfencing, or any other suitable material. The openings in the grate 250can be less one square inch in one example. In another example, theopenings in the grate 250 can be greater than one square inch, but lessthan half an inch wide at any point.

FIG. 3 provides a diagram of a container 300 experiencing anairbag-inflator deployment. The container 300 can be a cylinder,rectangle, or any other shape. In this example, the container 300includes an upper baffle 310 and a lower baffle 320 built into thecontainer 300 itself. Because the baffles 310, 320 are integrated withthe container 300, the container 300 includes a door 330 that providesaccess to the interior of the container 300. To load or unload thecontainer, a user can open the door 330 via the handle 335 and accessthe interior of the container 300.

In the example of FIG. 3, the container 300 includes five inflators 340.A container 300 can be sized to hold more than five inflators 340,however, and this quantity is merely chosen as one example. In practice,a particular container design can be tested to establish a “containableload” for the container. For example, the container can be subjected tothe “DOT Bonfire” test (also known as the “UN6(c) Bonfire Test”) with asingle inflator, then two inflators, and so on, until the container isunable to perform suitably. After establishing the maximum inflator loadthat a container can handle, a safety factor can be applied to establisha containable load. For example, 80% of the maximum can be used toestablish a containable load. In that example, a container design thatcan contain up to 20 inflators in a DOT Bonfire test would have acontainable load of 16 inflators.

In the example of FIG. 3, one of the five inflators 340 has deployed.The deployment has ejected several pieces of shrapnel 345 from theinflator 340. In practice, the size, number, and makeup of the shrapnel345 can vary greatly from one deployment to the next. In some cases, theinflator 340 itself may propel itself in various directions as thepropellant escapes the body of the inflator 340. As shown in FIG. 3, theshrapnel 345 impacts the sidewalls of the container 300 as well as theupper and lower baffles 310, 320 of the container 300. In each case, theshrapnel is redirected from the wall or baffle back into the container300.

Meanwhile, gases 350 expelled from the deployed inflator 340 can travelbetween the upper and lower baffles 310, 320 of the container and escapeinto the atmosphere. The distance between the upper and lower baffles310, 320 can be optimized to provide the smallest opening without undulyrestricting the flow of gas 350. This size can depend on the containableload for the container 300, as a larger containable load will require alarger exit port for gases 350. In practice, the baffles 310, 320 can beoriented such that they allow sufficient venting for a deployedcontainable load while maintaining the smallest opening possible.Additionally, the lengths of the baffles 310, 320 can be optimized toreduce the chance of shrapnel 345 exiting the container 300 while stillallowing gas 350 flow. For example, the overlapping portions of theupper and lower baffles 310, 320 can be increased or decreased relativeto the overlap shown in FIG. 3.

FIG. 4 provides an illustration of an example container 400. Thecontainer 400 of FIG. 4 includes a lattice structure forming arectangular box. For example, the container 400 includes multiplesidewall lattices 410, a rotatable top lattice 430, and a rotatablefront lattice 420. While this example depicts both the top and frontlattices 430, 420 as rotatable, the container 400 can also have only oneof those lattices rotatable while the other is fixed. However, havingboth lattices 430, 420 rotatable provides a larger opening for loadingand unloading the container 400. The top and front lattices 430, 420 caninclude a locking mechanism that locks the lattice structure 410, 420,430 together.

The lattices can be constructed from wire mesh, such as a metal wire orfencing. The thickness of the wire can be between about 0.09 inches and0.6 inches, in one example. The openings in the lattice structure can besized such that a sphere having a diameter greater than 0.5 inches wouldnot fit through the openings. Other sizes can be used as well. If thelattice structure has openings that are small enough, then an inner meshlayer is not necessary.

In the example of FIG. 4, however, various inner mesh layers 440, 450,and 460 are shown. Mesh layer 440 is shown in greater detail in FIG. 4C,mesh layer 450 is shown in greater detail in FIG. 4B, and mesh layer 460is shown in greater detail in FIG. 4C. Although they take differentshapes, each mesh layer 440, 450, 460 includes openings 442, 452, and462, respectively, that are sized to prevent shrapnel from passingthrough the mesh layer while allowing gases to vent through. Theseopenings 442, 452, 462 can be sized such that a sphere having a diameterof 0.25 inches or greater cannot pass through the mesh layer. Larger orsmaller openings 442, 452, 462 can be used. Although the mesh layers440, 450, 460 are shown as covering only a small portion of a lattice410, in practice a mesh layer can cover an entire lattice. In someexamples, each lattice component of the container 440 includes aninterior mesh layer.

In some examples, an environmental barrier can be used with thecontainer 400 to prevent rain or other moisture from entering thecontainer 400. For example, a plastic sheet can be secured to the top ofthe container to prevent fluid from dropping down into the container 400while also allowing the sides of the container 400 to vent gases. Insome examples, the environmental barrier can cover multiple sides of thecontainer 400. The environmental barrier can be configured such that itreleases from the container 400 or rips apart when deployment occurs.

FIG. 5 is an illustration of an example container 500 constructed fromreadily available materials such as steel plates and a grate. In thisexample, the container 500 includes four sidewalls 510 joined togethervia 90-degree brackets 540 and fasteners 545. Although fasteners 545 areshown here, other methods, such as welding, could be used instead. Thesidewalls 510 can be made from a strong, solid material such as a steel.Other materials can be used as well, with varying thickness based on thestrength of the material. Regarding steel, an example type of steelplate that can be used for a sidewall 510 is 0.25-inch-thick 4130 steel.These types of steel plates can be purchased off the shelf in a 2-footby 2-foot configuration, for example.

An example bracket 540 that can be purchased off the shelf is90-degree-angle steel, 0.25-inch-thick, 2 feet long, and 2 inches wideand deep. The brackets 540 can be positioned such that they extendbeyond the base of the sidewalls 510, as shown in FIG. 5, such that thebrackets 540 are the only components of the container 500 touchingsupporting the container 500 when positioned on flat ground.

A top plate 520 can be used to seal the top portion of the container500. The top plate 520 can be made from a similar steel plate as usedfor the sidewalls 510. The top plate 520 can be coupled to one of thesidewalls 510 via a hinge joint 530. In this example, the hinge joint530 spans one edge of the top plate 520, although in other examples thehinge joint 530 can be smaller, such as an embodiment using two or threehinge joints 530. The top plate 520 can include a locking mechanism thatlocks the top plate to one of the sidewalls 510 when closed.

A grate 550 can be coupled to the sidewalls 510 via one or more brackets540. The grate 550 can be an off-the-shelf item, such as a 2-foot by2-foot grate with slats having a height of 1 to 1.5 inches, width of0.25 inches, and about 1 inch between slats. These types of grates arecommonly used for roads and sidewalks, for example. Other types ofgrates or mesh can be used as well, such as a metal-wire mesh,chain-link fencing, or other suitable types. An additional steel platecan optionally be attached to the base of the brackets 540, such thatthe container 500 is fixed on the optional steel plate and includes agap between the optional steel plate and the grate 550. Fixing thecontainer 500 to the steel plate improves safety in the event of atip-over, due to fire, explosions, or an accident involving thetransport vehicle.

When deployment occurs within the container 500 of FIG. 5, gas canescape through the grate 550 of the container 500. In some examples, thegrate 550 can be sized such that no shrapnel can pass through the grate550. In other examples, the grate 550 can be sized to allow smallshrapnel pieces to pass through the grate 550. However, because thegrate 550 is at the bottom of the container 500, the shrapnel would dominimal damage, especially when the container 500 is placed on theground or on top of a solid surface, or when the steel plate is fixed tothe legs of the container below the grate.

In some examples, wheels can be affixed to the container 500 to allowthe container 500 to be more easily moved from one location to another.For example, commonly available caster wheels can be mounted to thecontainer 500. In one example, metal fasteners are used to fasten thecaster wheels to the container 500. Similar wheels can be attached toany of the containers disclosed herein.

Although FIG. 5 shows a container with solid sides, a solid top, and agrate on the bottom, other configuration are also possible. For example,the grate can be placed on any side of the container, or on the top ofthe container. In some examples, only one grate is used and theremaining surfaces are solid. In other examples, multiple grates areused and the remaining surfaces are solid. In yet other examples, all ofthe surfaces are solid and no grates are used. Any combination can beused based on the intended use of the container.

FIG. 6 provides an illustration of an example embodiment of a disposalcontainer 600 within which the container 500 from FIG. 5 is place. Insome examples, the container 500 of FIG. 5 can be used directly as adisposal container, for example by applying heat to the container 500sufficient to trigger inflator deployment within the container 500. Inother examples, the container 500 can be placed within a larger disposalcontainer 600 that can capture any shrapnel exiting the smallercontainer 500.

As shown in FIG. 6, for example, the disposal container 600 can includesolid walls 610, including a base 610, that can capture any shrapnelejected through the grate 550 of the container 500 inside the disposalcontainer 600. The disposal container 600 can include a vented lid 620that allows gases 630 from deployed inflators to exit the disposalcontainer 600. In some examples, the disposal container 600 can workwithout any lid at all, especially in cases where the container 500inside the disposal container 600 is expected to retain shrapnel.

Although FIG. 6 shows the container 500 of FIG. 5 within the disposalcontainer 600, any type of container can be placed inside the disposalcontainer 600. For example, the containers of FIG. 1, 3, or 4 can beplaced inside the disposal container 600. In some examples, the disposalcontainer 600 is sized to accommodate multiple transport containers. Inthat example, a single disposal container 600 can be used to “cook off”inflators within multiple transport containers. This can make theprocess more efficient depending on the facilities used to heat thedisposal container 600. The transport containers may also be exposed toan open, uncontained heat such as a flame for the purpose of disposingof the inflators.

During the disposal process, large amounts of energy can be releasedfrom inflators by the combustion of inflator propellant. A singlepassenger-side airbag inflator can release 4 moles of matter, in theform of gas, at temperatures in excess of 400 degrees Celsius. FIG. 7provides an illustration of an energy recovery system 700 that can beused to recover energy produced by inflator propellant combustion. Theexample of FIG. 7 shows three of the containers 300 described withrespect to FIG. 3. The containers 300 are placed on a heating surface710 that can accommodate several containers 300. Heat 720 can be appliedto the heating surface 710, or applied directly to the containers 300 insome examples. In one example the heating surface 710 can be a largegrate that allows flames 720 to pass through and contact the containers300. In another example, the heating surface 710 is a solid surface thatis heated via flames 720 and then transfers heat to the containers 300via conduction. Any type of heat transfer mechanism can be used,including conduction, convection, induction, or radiation.

As shown in FIG. 7, a hood 730 can be attached to each container 300.The hood 730 can be configured to seal around the top of the container300, forcing any gas produced via deployment to enter the hood 730. Thehood 730 can connect to piping 740 that routes the high-energy gas awayfrom the container 300. In the example of FIG. 7, several hoods 730connect to piping 740 that joins together and routes toward a filter750.

The filter 750 can prepare the gas flow for entering a turbine 760.Based on the needs of the turbine 760, the filter 750 can be designed toprovide an appropriate level of filtering. For example, the filter 750can be a simple grate or mesh that prevents solid shrapnel particlesfrom entering the turbine 760. In another example, the filter 750 caninclude a filter medium, such as paper or charcoal, that removes certainparticulates from the gas flowing through the piping 740. The filteredgas then enters the turbine 760 and causes the turbine 760 to producepower that can be harnessed and reused. For example, the turbine 760 canbe used to power a heating mechanism that produces and applies heat tothe heating surface 710. Other energy-recovery mechanisms can be used inplace of a turbine. For example, the expelled gases can be used to heata boiler.

In one example, the containers are heated using excess heat created froma process unrelated to the inflators. For example, the containers can beheated using excess heat from a power generation process at a coal plantor nuclear plant. In that example, the containers can be made tointerface with a heat source that provides rejected heat from the powergeneration process. For example, if the heat is rejected from the powergeneration process via air, the exhaust manifold that exhausts theheated air can be attached to a container. The container can include ana manifold that mates with the exhaust manifold to direct the heated airtoward the inflators in the container. In an example where the heat isrejected from the power generation process via a liquid, the containercan include a heat exchanger that can intercept the heated liquid,extract heat from the liquid, and direct the liquid back to its originalpath. The shape and size of the container can be modified to fit anytype of heat source. Using heat waste from an industrial process canlower the costs for disposing of the recalled inflators.

FIG. 8 is a flowchart of an example method for handling airbaginflators. Stage 810 of the method can include placing a live airbaginflator in a vented container, such as one of the containers disclosedabove with respect to FIGS. 1-7. The container can be shaped to holdmultiple live airbag inflators, and can withstand a deployment of anairbag inflator by retaining the deployed airbag inflator and shrapnelassociated therewith while allowing gas associated with the deploymentto exit the container.

Stage 820 of the method can include positioning the container in or on atransport vehicle. This can include, for example, lifting the containerby hand and placing it in a truck bed. In another example, a forklift,crane, or other lifting mechanism can be used to lift the container andmove it. The transport vehicle can be any type of vehicle, including acar, truck, ship, train, or airplane. In some examples, the container isalready positioned on a transport vehicle before stage 810 takes place.For example, a container can be constructed using a standard inter-modalshipping container. The shipping container can include a latticestructure similar to that described with respect to FIG. 4. In thatexample, the shipping container can be positioned on the trailer of atruck before the airbag inflators are positioned in the container.

Stage 830 can include measuring a first weight of the containerincluding the live airbag inflator. For example, the container can beplaced on a large scale to determine a total weight. In another example,a lifting mechanism can measure the weight of the container as thecontainer is positioned on a transport vehicle at stage 820. This stagecan also include noting the total number of inflators in the container,as well as the number of driver-side inflators, passenger-sideinflators, side-impact inflators, and curtain inflators.

Stage 840 includes applying heat to the container sufficient to deploy alive airbag inflator. This can include, for example, applying a flamedirectly to the container. In another example, heated air can bedirected toward the container. In yet another example, a heating surfacecan conduct heat into the container. In one example, the container isheated such that the inflators reach a minimum internal temperature of130 degrees Celsius. In another example, the container is heated suchthat the inflators reach a minimum temperature of 180 degrees Celsius.

In yet another example, the container is heated such that the inflatorsreach a minimum temperature of 200 degrees Celsius.

Stage 850 can include measure a second weight of the container includingthe inflator. For example, at the conclusion of the heating process, thecontainer can be placed on a scale. A single passenger-side inflatortypically loses approximately 80-140 grams of mass due to a deployment.A single driver-side inflator typically loses approximately 20-50 gramsof mass due to a deployment. A single side-impact inflator typicallyloses approximately 20-40 grams of mass due to a deployment.

Stage 860 can include calculating a difference between the first weightand the second weight. The difference between these two weights canindicate whether any inflators within the container have deployed, andif so, how many. The difference between the first and second weights canalso be divided by the number of inflators in the container to determinean average weight difference per inflator.

Based on the difference between the first and second weight being abovea threshold value, at stage 870, the exploded inflator can be removedfrom the container. The threshold value can be based on the number ofinflators in the container. As an illustration, an example container canhold 10 driver-side inflators and 10 passenger-side inflators. Anestimation can predict that the driver-side inflators will lose 300grams (30 grams each) if all inflators deploy, while the passenger-sideinflators will lose 1000 grams (100 grams each) if they all deploy. Inthat example, the difference between the first and second weight shouldbe above a threshold that is close, or equal to, 1300 grams. If thedifference is substantially less than 1300 grams in that example, thenthe container can undergo further heating, including being heated at ahigher temperature than previously. After the additional heating, areplacement second weight can be obtained and used to calculate a weightdifference from the first weight.

In one example, a large-scale shipping container can be used fortransporting airbag inflators. For example, a commonly used 30-yarddumpster or dump truck bed rated for 20-ton gravel loads can be used. Asmaller metal shipping container could also be nested inside a largerone to achieve sufficient container integrity, such as small dumpsterhoused inside a larger dumpster. The purpose of the shipping containercan be to prevent inflator metal fragments from exiting the sidewall ofthe container and directing all energy that results from inflatordeployments up toward the top of the container.

Another purpose of the shipping container can be to prevent propagationof an explosion. In some examples, recalled inflators can havecharacteristics that create a risk of an explosion propagating to nearbyinflators. This can be specified in the new classification, orreclassification, that applies to recalled inflators. The risk ofpropagation can be lessened by controlling the size of the “containableload” used with each container. However, the containers can be designedto withstand propagation and prevent explosions from propagating acrosscontainers.

Continuing the large-scale shipping container example, a containmentblanket can be used to prevent shrapnel from escaping the container. Thecontainment blanket can include a net or mesh structure that preventsshrapnel from passing through the containment blanket. The blanketingstructure on top of the inflator load can prevent over-pressurization ofthe shipping container if inflators deploy inside the container,allowing inflator combustion gases to vent while preventing metalinflator fragments of critical mass from exiting the top of thecontainer. Examples of suitable material for the containment blanket areexpanded steel mesh or grates with properly sized openings. Anotherexample of a suitable material is a chain-link fencing material.

The large-scale shipping container can also be implemented in a similarmanner with respect to rail cars or barges, such that the inflators canbe shipped via rail or water.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1-20. (canceled)
 21. A method for transporting airbag inflators thathave ammonium-nitrate-based propellant, comprising: placing theinflators into a container including: at least one metal gratecomprising a plurality of connected slats, wherein the slats arepositioned to prevent a sphere having a diameter greater than 1 inchfrom passing through the grate, and wherein the at least one metal grateforms a side of the container and at least partially defines abreathable containment space; and a hinged door for adding and removingthe airbag inflators; and transporting the container.
 22. The method ofclaim 21, wherein the container further comprises a solid steel platethat at least partially defines the breathable containment space. 23.The method of claim 21, wherein the container further comprises aplurality of metal grates.
 24. The method of claim 21, wherein the atleast one metal grate is selected from one of a traffic grate, drivegrate, and metal-bar grate.
 25. The method of claim 21, wherein each ofthe plurality of slats has a height of 1 to 1.5 inches.
 26. The methodof claim 21, wherein the slats of the plurality of slats have about 1inch between them.
 27. The method of claim 21, wherein each of theplurality of slats has a width of about 0.25 inches.
 28. A container fortransporting airbag inflators with ammonium-nitrate-based propellant,comprising: at least one metal grate comprising a plurality of connectedslats, wherein the slats are positioned to prevent a sphere having adiameter greater than 1 inch from passing through the grate, and whereinthe at least one metal grate forms a side of the container and at leastpartially defines a breathable containment space; and a hinged door foradding and removing the airbag inflators.
 29. The container of claim 28,further comprising a solid steel plate that at least partially definesthe breathable containment space.
 30. The container of claim 28, furthercomprising a plurality of metal grates.
 31. The container of claim 28,wherein the at least one metal grate is selected from one of a trafficgrate, drive grate, and metal-bar grate.
 32. The container of claim 28,wherein each of the plurality of slats has a height of 1 to 1.5 inches.33. The container of claim 28, wherein the slats of the plurality ofslats have about 1 inch between them.
 34. The container of claim 28,wherein each of the plurality of slats has a width of about 0.25 inches.35. A container for transporting airbag inflators withammonium-nitrate-based propellant, comprising: a plurality of metalgrates, each metal grate comprising a plurality of connected slatspositioned to prevent a sphere having a diameter greater than 1 inchfrom passing through the grate, and wherein the plurality of metalgrates form a respective plurality of sides of the container and atleast partially define a breathable containment space; and a removabledoor for adding and removing the airbag inflators.
 36. The container ofclaim 35, wherein the removable door is a hinged metal grate.
 37. Thecontainer of claim 35, wherein the removable door is configured to bemechanically fastened to at least one of the metal grates.
 38. Thecontainer of claim 35, wherein the removable door is a solid steelplate.
 39. The container of claim 35, wherein each of the plurality ofmetal grates is selected from one of a traffic grate, drive grate, andmetal-bar grate.
 40. The container of claim 35, wherein the slats of theplurality of slats have about 1 inch between them.